JPH03268993A - Recording material - Google Patents

Abstract

PURPOSE:To ensure that coloring and storage properties are satisfactory and other installation requirements are met by adding a fluorene derivative having an amino group substituted by an alkyl group with an amino residual group or an amido residual group in the 6th position as an electron-donative colorless dry. CONSTITUTION:A fluorene derivative having an amino group substituted by an alkyl group containing an amine or amido residual group in the 6th position, for example, diisopropylnaphthalene in which a compound is dissolved, as an electron-donative colorless dye, is emulsified and dispersed in an aqueous solution of sodium salt, part of polyvinylbenzenesulfonic acid, to obtain an emulsion. Separately aqueous melamine and formaldehyde solutions are thermally stirred to obtain an aqueous transparent initial polymer solution of melamine and formaldehyde. This aqueous solution is mixed with the mentioned emulsion, and an aqueous solution of polyvinylalcohol and starch powder are added to this dispersion liquid. In addition, water is added to this adduct to condition a microcapsule-dispersed, liquid, and then it is applied to a sheet and dried to obtain a capsule sheet containing an electron-donative colorless dye. Next, this sheet is placed over an electron-receptive compound sheet and these sheets are given a load to allow color development.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a recording material, and particularly to a recording material with improved color development and storage stability.

(Prior Art) Recording materials using electron-donating colorless dyes and electron-accepting compounds are already well known as angry pressure paper, thermal paper, angry light pressure sensitive paper, electrically conductive thermal recording paper, thermal transfer paper, and the like. For example, British Patent No. 2140449, U.S. Patent No. 4480052, U.S. Patent No. 4436920, Japanese Patent Publication No. 60-23992, Japanese Unexamined Patent Publication No. 57
-179836, 60-123556, 60-12
I am familiar with 3557 etc.

As a recording material, in recent years (11 color density and color sensitivity,
(2) Research is being carried out to improve properties such as the fastness of coloring bodies.

The present inventors have investigated the oil solubility, solubility in water, partition coefficient, pKa, polarity of substituent, position of substituent, crystallinity when mixed, for each of the electron donating colorless dye and the electron accepting compound. Focusing on characteristics such as changes in solubility, we have pursued the development of good materials for recording materials and recording materials.

(Object of the Invention) Therefore, an object of the present invention is to provide a recording material using a material that has good color development and storage stability, and also satisfies other requirements.

(Structure of the Invention) The object of the present invention is to provide an electron-donating colorless dye containing a fluorane derivative having an amino group substituted with an alkyl group containing an amine residue or an amide residue at the 6-position. Achieved through recording materials.

In the fluoran derivative according to the present invention, in order to obtain a black to green hue, it is preferable that both the 2-position and the 6-position are substituted with an amino group.

The 5th and 7th positions are preferably hydrogen atoms from the viewpoint of color development hue and color density.

Among these, those represented by the following general formula (I) are preferred.

S R (wherein R,, R, and R1 are alkyl groups, alkenyl groups, aralkyl groups, alkynyl groups, aryl groups, and hydrogen atoms; R2 is hydrogen atoms, alkyl groups, alkoxy groups,
Halogen atom, R4 is hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, alkoxy group, aryloxy group, alkylthio group, halogen atom, substituted amino group, cyano group, nitro group, acyl group, trihalomethyl group , a sulfamoyl group, l is an integer from 1 to 5,
R6 is a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkynyl group, an acyl group, an alkylsulfonyl group, an arylsulfonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a substituted carbamoyl group, and ring A is a hetero an aromatic acid which may contain atoms, R represents a linear or branched alkylene which may contain an ether, thioether, or ester bond;
The nitrogen ring or ring A may have a plurality of the same or different substituents, in which case the substituents are an alkoxy group,
represents a halogen atom or a nitro group, or R1 and R4 may be combined with each other to form a ring, in which case they represent a 5- to 12-membered ring having an oxygen atom, a sulfur atom, or a nitrogen atom) In formula (1), the groups represented by R1 and R3 further include an alkyl group, an alkenyl group, an alkynyl group,
It may be substituted with an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, a halogen atom, a substituted amino group, a cyano group, a nitro group, an acyl group, a trihalomethyl group, a sulfamoyl group, a heterocyclic residue, or the like.

R1 is H, CH3, CnHzn-IYZ.

(n is an integer from 2 to 10, m is an integer from 1 to 5, Y and Z are hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, alkoxy groups, aryloxy groups,
(representing an alkylthio group, a halogen atom, a substituted amino group, a cyano group, a nitro group, an acyl group, a trihalomethyl group, a sulfamoyl group, a heterocyclic residue, etc.) are preferred.

As R1 and R1, methyl, ethyl, propyl, benzyl, butyl, phenyl, tolyl and the like are particularly preferred.

In the above formula, the group represented by R2 has a hydrogen atom and a carbon atom number of 1.
An alkyl group having from 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and a halogen atom are preferred, and a methyl group, an ethyl group, a chlorine atom, and a hydrogen atom are particularly preferred.

In the above formula, the group represented by R5 is a hydrogen atom, and has 1 to 1 carbon atoms.
8 is preferably an alkyl group, particularly a hydrogen atom or a methyl group. When R1 is a hydrogen atom, R4 is preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. When R is a methyl group, R4 is preferably a trifluoromethyl group, a nitro group, a cyano group, a sulfamoyl group, or the like.

In the above formula, ring A, a benzene ring, a naphthalene ring, a pyridine ring, a pyrazine ring, an indole ring and the like are preferred, with a benzene ring being particularly preferred.

Furthermore, ring A may contain an alkyl group, a halogen atom, a nitro group, a cyano group, an alkoxy group, or the like.

In the above formula, R.

The group represented by -CnHgn-sYZ.

nH1n -CnHznOC++Hzs +YZ, 10O□R1+ (n is an integer from 2 to 1O, m is an integer from 1 to 5, !, p
, q are each independently an integer from O to lo, Y and Z are hydrogen atoms, an alkyl group, an alkenyl group, an alkynyl group,
Represents an aryl group, an alkokene group, an aryloxy group, an alkylthio group, a halogen atom, a substituted amino group, a cyano group, a nitro group, an acyl group, a trihalomethyl group, a sulfamoyl group, a heterocyclic residue, etc., where X is an oxygen atom, Sulfur atom, sulfonyl group, sulfinyl group, Ar is aryl group, R1,1°, 11 is alkyl group, aryl group, R
11 represents a hydrogen atom, an alkyl group, or an aryl group.) In the above formula, the group represented by R is a linear or branched group that may contain an ether, thioether, or ester bond having 1 to 10 carbon atoms. Preferred are alkylenes, particularly straight-chain alkylenes having 1 to 6 carbon atoms.

Specific examples of fluoran derivatives according to the present invention are shown below, but the present invention is not limited thereto.

CH.

C,H.

zHs (2) CH3 Ct’As (5) L (3) C! 1ls (6) C, H Shizuku-Isamu C friend.

C! l(.

CtHs C1K.

(10) C3H1-Il Js C.HS Examples include.

Electron-donating colorless dyes according to the present invention include conventionally known triphenylmethane phthalide compounds, fluoran compounds, phenothiazine compounds, indolyl phthalide compounds, leuco auramine compounds, rhodamine lactam compounds, triphenyl It can be used in combination with various compounds such as methane compounds, triazene compounds, spiropyran compounds, and fluorene compounds.

Specific examples of phthalides are given in U.S. Reissue Patent Specification No. 23.0.
No. 24, U.S. Patent Specification No. 3.491111, U.S. Patent No. 3
, 491,112, 3.491.116 and 3,509.174; specific examples of fluorans are U.S. Pat.
, No. 787, No. 3,641,011, No. 3,46
No. 2,828, No. 3,681.390, No. 3,9
No. 20.510, No. 3.959,571, and specific examples of subirodipyrans are given in U.S. Patent Specification No. 3971.808.
No. 3,775,424 and U.S. Pat. No. 3,853,869 for pyridine and pyrazine compounds.
No. 4.246318, and specific examples of fluorene compounds are described in Japanese Patent Application No. 61-240989.

Examples of the electron-accepting compound used in the recording material of the present invention include phenol derivatives, salicylic acid derivatives, metal salts of aromatic carboxylic acids, acid clay, bentonite, novolac resins, metal-treated novolac resins, and metal complexes.

Examples of these are Special Publication No. 9309 of 1972 and Special Publication No. 1 of 1973.
No. 4039, JP-A-52-140483, JP-A-48
-51510, JP-A-57-210886, JP-A-58-87089, JP-A-59-11286, JP-A-60-176795, JP-A-61-95988, etc.

Examples of electron-accepting compounds include bisphenol A, 2
．． 2-bis(3-methyl-4-hydroxyphenyl)propane, 2.2-bis(4-hydroxyphenyl)butane, 1.1-bis(4-hydroxyphenyl)butane, 1.1-bis(4- hydroxyphenyl)-2-ethylhexane, 1,1-bis(3-chloro-4-hydroxyphenyl)-2-ethylbutane, bis(3-allyl-
4-hydroxyphenyl) sulfone, 1,7-bis(4
-hydroxyphenylthio)-3,5-dioxahebutane, (4-hydroxyphenyl)=(4-isopropoxyphenyl) sulfone, 4-hydroxybenzoic acid benzyl ester, 2.4 dihydroxybenzoic acid -β-phenoxyethyl ester , 2,4-dihydroxybenzoic acid-
α-Methyl-β-(3-methoxyphenoxy)ethyl ester, 1,3-bis(4-hydroxyphenyl)propane, 2-(2,4-dihydroxydiphenyl)-2-funylbroban, 3,5-bis( Examples include zinc α-methylbenzyl) salicylate.

When the recording material of the present invention is used for thermal paper,
2-144,989, Japanese Patent Application No. 62-244.883, etc. Specifically, the electron-donating colorless dye and the electron-accepting compound are used after being pulverized and dispersed in a dispersion medium to a particle size of 10 μm or less, preferably 3 μm or less. As the dispersion medium, an aqueous polymer solution having a concentration of about 0.5 to 10% is generally used, and dispersion is carried out using a ball mill, sand mill, horizontal sand mill, attritor, colloidal mill, or the like.

The ratio of the electron-donating colorless dye to the electron-accepting compound used is preferably between 1=10 and 1:1 by weight, and particularly preferably between 1:5 and 2=3.

At that time, a thermofusible substance can be included in the thermosensitive coloring layer in order to improve thermal responsiveness. Representative thermofusible substances include aromatic ethers, thioethers, esters, and/or aliphatic amides or ureides.

Examples of these are JP-A-58-57989 and JP-A-58-87.
No. 094, No. 61-58789, No. 62-10968
No. 1, No. 62-132674, No. 63-151478
No. 63-235961, Japanese Patent Application Publication No. 1-4447,
It is described in No. 1-37070.

Examples of thermofusible substances include phenethyl biphenyl ether, benzyloxynaphthalene, benzylbiphenyl, 1,2-diphenoxyethane, 1,2-di-m-)lyloxyethane, 1-phenoxy-2-P-methoxy Phenoxyethane, 1-p-methoxyphenoxy-2-o
-Chlorphenoxyethane, 1,2-di-P-fluorophenoxyethane, 1,3-di-P-methoxyphenoxypropane, 1,2-di-p-methoxyphenoxypropane, 1-phenoxy-2-P-methoxyphenoxypropane , 1-p-methoxyphenoxyethoxy-2-1
)-methoxyphenoxyethane, 1,2-di-p-methoxyphenylthioethane, p-methoxybenzyloxytolylmethane, (4methoxybenzyloxy)-(3-
Methyl-4chlorophenyl)methane, p-chlorobenzyloxy-P-ethoxyphenylmethane, and the like.

These are used in finely dispersed form at the same time as the electron-donating colorless dye or simultaneously with the electron-accepting compound. The amount used is 20% or more and 300% or less by weight, particularly preferably 40% or more and 150% or less, based on the electron-accepting compound.

Additives may be added to the thus obtained coating liquid as necessary to meet various requirements. Examples of additives include dispersing oil-absorbing substances such as inorganic fillers and polyurea fillers in the binder to prevent the recording head from becoming dirty during recording, and to improve the releasability of the head. Fatty acids, metal soaps, etc. are added to enhance the quality. Therefore, in addition to electron-donating colorless dyes and electron-accepting compounds that directly contribute to color development, thermofusible substances, pigments, waxes, antistatic agents, ultraviolet absorbers,
Additives such as a defoaming side, a conductive agent, a fluorescent dye, and a surfactant side are coated on the support to form a recording material.

Furthermore, if necessary, a protective layer may be provided on the surface of the heat-sensitive recording layer, two or more protective layers may be laminated as necessary, and in order to correct the curl balance of the support, or on the back side. A coating liquid similar to a protective layer may be applied to the back surface for the purpose of improving chemical resistance. An adhesive may be applied to the back side and a release paper may be further added to form a label.

Usually, the electron-donating colorless dye and the electron-accepting compound are dispersed in a binder and applied. Water-soluble binders are generally used, such as polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, epichlorohydrin-modified polyamide, and ethylene-
Examples include maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, polyacrylic acid, polyacrylic acid amide, methylol-modified polyacrylamide, starch derivatives, casein, and gelatin. Further, for the purpose of imparting water resistance to these binders, a water resistance agent may be added, or an emulsion of a hydrophobic polymer, specifically, a styrene-butadiene rubber latex, an acrylic resin emulsion, etc. may be added.

The obtained heat-sensitive coating liquid is applied to high-quality paper, high-quality paper with an undercoat layer, synthetic paper, plastic film, etc. From the viewpoint of dot reproducibility, it is particularly preferable to use a support having a smoothness defined by WAJIs-8119 of 500 seconds or more, particularly 800 seconds or more.

When providing an undercoat layer mainly composed of pigments on a support, all general organic or inorganic pigments can be used, but in particular those with an oil absorption of 40 cc/100 g or more as specified in JIS-5101. Preferred examples include calcium carbonate, barium sulfate, titanium oxide, talc, waxite, kaolin, calcined kaolin, aluminum hydroxide, amorphous silica, urea-formalin resin powder, polyethylene resin powder, and the like.

When applying these pigments to a support, the amount of pigment is 2
g/n or more, preferably 4 g/n (or more).

Binders used in the undercoat layer include water-soluble polymers and water-insoluble binders, and the binders may be used alone or in combination of two or more.

Examples of water-soluble polymers include methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, ethylene-maleic anhydride copolymer hydrolyzate, and isobutylene. -Maleic anhydride copolymer hydrolyzate, polyvinyl alcohol,
Examples include carboxy-modified polyvinyl alcohol and polyacrylamide.

As the water-insoluble binder, synthetic rubber latex or synthetic resin emulsion is generally used, and examples include styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, acrylic acid methylbutadiene rubber latex, and vinyl acetate emulsion. It will be done.

The amount of binder used is 3 to 100% by weight based on the pigment.
Preferably it is 5 to 50% by weight. Wax, anti-fading agent, surfactant, etc. may be added to the undercoat layer.

Pigments used as additives in the present invention include kaolin, calcined kaolin, talc, waxite, diatomaceous earth, calcium carbonate, aluminum hydroxide, magnesium hydroxide,
Zinc oxide, lithopone, amorphous silica, colloidal silica, calcined gypsum, silica, magnesium carbonate, titanium oxide, alumina, barium carbonate, barium sulfate, mica, microballoon, urea-formalin filler, polyester particles, cellulose filler, etc. Can be mentioned.

Examples of metal soaps include polyvalent metal salts of higher resin acids, such as zinc stearate, aluminum stearate, calcium stearate, and zinc oleate.

Further, in the present invention, it is preferable to use a wax having a melting point of 40 to 120''C in view of head matching properties for facsimile machines.

The wax has a melting point of 40 to 120°C, and includes paraffin wax, polyethylene wax, carnauba wax, microcrystalline wax, campria wax, montan wax, fatty acid amide wax, and the like. Among them, paraffin wax, microcrystalline wax, montan wax, and fatty acid amide wax are preferable, especially those having a melting point of 50 to 1
00°C paraffin wax, montan wax, and methylol stearamide are preferred.

The amount of wax used is 5 to 200% of the electron-donating colorless dye.
The amount of M is %, preferably 20 to 150% by weight.

As the hindered phenol compound, a phenol derivative in which at least one of the 2nd and 6th positions is substituted with a branched alkyl group is preferred.

Examples of ultraviolet absorbers include cinnamic acid derivatives, benzophenone derivatives, benzotriarylphenol derivatives, etc. For example, α-cyano-β-phenylbutyl cinnamate, 0-benzotriazolylphenol, 0-benzotriazolyl-P-chloro Phenol, 0-benzotriazolyl-2
, 4-di-t-butylphenol, and 0-benzotriazolyl-2,4-di-t-octylphenol.

Water-resistant agents include water-soluble initial condensates such as N-methylol urea, N-methylol melamine, and urea-formalin, nodialdehyde compounds such as glyoxal and glutaraldehyde, inorganic crosslinking agents such as boric acid and borax, polyacrylic acid, Examples include blend heat treatment of methyl vinyl ether-maleic acid copolymer, isobutylene-maleic anhydride copolymer, and the like.

Materials used for the protective layer include polyvinyl alcohol,
Carboxy-modified polyvinyl alcohol, vinyl acetate-acrylamide copolymer, silicon-modified polyvinyl alcohol, starch, modified starch, methylcellulose, carboxymethylcellulose, hydroxymethylcellulose, gelatins, gum arabic, casein, styrene-maleic acid copolymer hydrolyzate, Styrene-maleic acid copolymer half ester hydrolyzate, isobutylene-maleic anhydride copolymer hydrolyzate, polyacrylamide derivative, polyvinylpyrrolidone, polystyrene sodium sulfonate,
Water-soluble polymers such as sodium alginate, and water-insoluble polymers such as styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and vinyl acetate emulsion are used.

In addition, pigments, metal soaps, waxes, waterproofing agents, etc. may be added to the protective layer for the purpose of improving matching properties with the thermal head.

In addition, when coating the protective layer on the heat-sensitive coloring layer, a surfactant may be added to obtain a uniform protective layer. Examples of the surfactant include sulfosuccinic acid-based alkali metal salts, fluorine-containing surface An activator or the like is used. Specifically, G (
Sodium salts such as n-hexyl)sulfosuccinic acid and di(2-ethylhexyl)sulfosuccinic acid, or ammonium salts are preferred, but anionic surfactants are effective.

For use with pressure sensitive paper, U.S. Patent No. 2,505.47
No. 0, No. 2,505,471, No. 2゜505.489
No. 2,548,366, No. 2.712,507, No. 2,730,456, No. 2.730.457,
It can take various forms as described in prior patents such as No. 3,103.404, No. 3,418,250, and No. 4,010,038. It most commonly consists of at least one pair of sheets containing separately an electron-donating colorless dye and an electron-accepting compound.

A method of manufacturing capsules is described in U.S. Pat. No. 2.800.
457, a method using coacervation of a hydrophilic colloid sol described in British Patent Nos. 2,800,458, British Patent No. 867.797, British Patent No. 950,443, British Patent No. 98
Examples include interfacial polymerization methods described in US Pat. No. 9,264 and US Pat. No. 1091.076, and methods described in US Pat. No. 3,103.404.

In general, electron-donating colorless dyes are used alone or in combination as solvents (alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkylated terphenyl, alkylated terphenyl, etc.).
Synthetic oils such as chlorinated paraffin; vegetable oils such as cotton oil and castor oil; animal oils; mineral oils or mixtures thereof, etc.) are dissolved in microcapsules to produce paper, high-quality paper, plastic sheets, resin coatings, etc. A coloring agent sheet is obtained by applying it to ted paper, etc.

In addition, an electron-accepting compound and optionally additives, alone or in combination, are dispersed in a binder such as styrene-butadiene latex or polyvinyl alcohol, and are used together with pigments to support paper, plastic sheets, resin-coated paper, etc. A developing sheet is obtained by applying it to the body.

As a binder, the combination of carboxy-modified styrene-butadiene latex and water-soluble polymer improves light resistance,
It is preferable from the point of view of water resistance, and the average particle size of the pigment is 5.
．． From the viewpoint of color developing ability, it is preferable to use calcium carbonate with a particle size of 0 μ or less in an amount of 60% by weight or more of the total pigment.

The amount of the electron-donating colorless dye and the electron-accepting compound to be used depends on the desired coating thickness, the form of the pressure-sensitive recording paper, the capsule manufacturing method, and other conditions, and can be appropriately selected according to the conditions. Determining usage is easy.

(Examples of the invention) Examples are shown below, but the present invention is not limited thereto. Unless otherwise specified in the examples, wt%
represents.

Example-1 1) Preparation of capsule sheet containing electron-donating colorless dye 5 parts of a partial sodium salt of polyvinylbenzenesulfonic acid (manufactured by National Starch Co., Ltd., VER5A, Tl2O3) are dissolved in 95 parts of water. A sodium hydroxide aqueous solution was added to this to adjust the pH to 4.0. On the other hand, 100 parts of diisopropylnaphthalene in which 4.5% of the compound of Specific Example (8) of the electron-donating colorless dye was dissolved was emulsified and dispersed in 100 parts of a 5% aqueous solution of a partial sodium salt of the polyvinylbenzenesulfonic acid. An emulsion with a particle size of 0μ was obtained.

Separately, 6 parts of melamine, 11 parts of a 37% by weight formaldehyde aqueous solution, and 30 parts of water were heated and stirred at 60° C. to obtain a transparent aqueous solution of melamine-formalbihyde prepolymerized product. This aqueous solution was mixed with the above emulsion. While stirring, adjust the pH to 6.0 with an aqueous phosphoric acid solution. The solution temperature was raised to 65°C, and stirring was continued for 6 hours. This capsule liquid was cooled to room temperature and adjusted to pH 9.0 for tP1 with an aqueous sodium hydroxide solution.

To this dispersion, 200 parts of a 10% by weight polyvinyl alcohol aqueous solution and 50 parts of starch particles were added and water was added to prepare a solution of a microcapsule dispersion with a solid content concentration of 20%.

This coating liquid was applied to a 50 g/nf base paper using an air knife coater so that the solid content was 5 g/m, and dried to obtain a capsule sheet containing an electron-donating colorless dye.

2) Preparation of electron-accepting compound sheet 3. Zinc 5-bis(α-methylbenzyl)salicylate 1
A dispersion liquid consisting of 4 parts of calcium carbonate, 80 parts of calcium carbonate, 20 parts of zinc oxide, 1 part of sodium hexametaphosphate and 200 parts of water was dispersed using a sand glider so that the average particle size was 3 microns. To this dispersion, 100 parts of a 10% PVA aqueous solution and 10 parts of carboxine-modified SBR latex (as solid content) were added, and water was added so that the solid content concentration was 20%.
A coating liquid was obtained. Apply 5゜0g of this coating liquid to 50g/rd base paper.
/rf+ solid content was coated using an air knife coater and dried to obtain an electron-accepting compound sheet.

The surface of the microcapsule sheet containing an electron-donating colorless dye is
When it was layered on an electron-accepting compound sheet and subjected to a load of 400 kg/d to develop color, the coloring dye was deep black, and the colored image obtained showed good light resistance.

Example-2 20 g each of the compound of specific example (9) which is an electron-donating colorless dye, bisphenol A which is an electron-accepting compound, and 1-phenoxy-2-(4-methoxyphenoxy)propane which is a thermofusible compound. was dispersed in a ball mill overnight with 100 g of 5% polyvinyl alcohol (Kuraray PVAl05) aqueous solution to give a volume average particle size of 3 μm. On the other hand, 80 g of calcined kaolin (Anisilex-93) was dispersed with 160 g of a 0.5% solution of sodium hexametaphosphate using a homogenizer.

After dispersing as described above, each dispersion was mixed in a proportion of 5 g of an electron-donating colorless dye dispersion, 10 g of an electron-accepting compound dispersion]Og, a diaryloxycalcane compound dispersion, and 22 g of a calcined kaolin dispersion, and then A coating liquid was obtained by adding 4 g of an emulsion of zinc stearate and 5 g of a 2% aqueous solution of sodium (2-ethylhexyl)sulfosuccinate. The coating solution No. 2 was applied onto high-quality paper with a basis weight of 50 g/rrf using a wire bar so that the dry coating amount was 6 g/rd, and calendering was performed to obtain a coated paper.

The coated paper obtained as described above was coated with a head voltage of 24 V and a pulse cycle using a thermal printing experimental device equipped with a Kyocera ■ thermal head (KLT-216-8MPD1) and a 100 kg/cj pressure roll just before the head. 10
While using the pressure roll under the conditions of m5, the pulse width was set to 1.
．． 0, and check the print density using Macbeth reflection densitometer RD.
The zero color density measured at -918 was 1.37. The colored image obtained also showed good plasticizer resistance.

Example-3 The compound of Specific Example (9) of Example-2 was converted into Specific Example 0 (to)
A coated paper was obtained in the same manner as in Example 2 except that the compound was changed. When the color was developed in the same manner as in Example 2, the color density was 1.34. Moreover, the obtained colored image showed good plasticizer resistance.

Claims (1)

[Claims] In a recording material using an electron-donating colorless dye and an electron-accepting compound, the electron-donating colorless dye contains a fluorane derivative having an amino group substituted with an alkyl group containing an amine residue or an amide residue at the 6-position. Recording material characterized by